yii2-authclient is an extension that adds OpenID, OAuth, OAuth2 and OpenId Connect consumers for the Yii framework 2.0. In yii2-authclient prior to version 2.2.15, the Oauth2 PKCE implementation is vulnerable in 2 ways. First, the `authCodeVerifier` should be removed after usage (similar to `authState`). Second, there is a risk for a `downgrade attack` if PKCE is being relied on for CSRF protection. Version 2.2.15 contains a patch for the issue. No known workarounds are available.

yii2-authclient is an extension that adds OpenID, OAuth, OAuth2 and OpenId Connect consumers for the Yii framework 2.0. In yii2-authclient prior to version 2.2.15, the Oauth1/2 `state` and OpenID Connect `nonce` is vulnerable for a `timing attack` since it is compared via regular string comparison (instead of `Yii::$app->getSecurity()->compareString()`). Version 2.2.15 contains a patch for the issue. No known workarounds are available.

Yii is an open source PHP web framework. yiisoft/yii before version 1.1.29 are vulnerable to Remote Code Execution (RCE) if the application calls `unserialize()` on arbitrary user input. An attacker may leverage this vulnerability to compromise the host system. A fix has been developed for the 1.1.29 release. Users are advised to upgrade. There are no known workarounds for this vulnerability.

web\ViewAction in Yii (aka Yii2) 2.x before 2.0.5 allows attackers to execute any local .php file via a relative path in the view parameeter.

Yii 2 v2.0.45 was discovered to contain a cross-site scripting (XSS) vulnerability via the endpoint /books. NOTE: this is disputed by the vendor because the cve-2022-31454-8e8555c31fd3 page does not describe why /books has a relationship to Yii 2.

SQL injection vulnerability found in Yii Framework Yii 2 Framework before v.2.0.47 allows the a remote attacker to execute arbitrary code via the runAction function. NOTE: the software maintainer's position is that the vulnerability is in third-party code, not in the framework.

Yii Yii2 Gii before 2.2.2 allows remote attackers to execute arbitrary code via the Generator.php messageCategory field. The attacker can embed arbitrary PHP code into the model file.

Yii Yii2 Gii through 2.2.4 allows stored XSS by injecting a payload into any field.

`yiisoft/yii` before version 1.1.27 are vulnerable to Remote Code Execution (RCE) if the application calls `unserialize()` on arbitrary user input. This has been patched in 1.1.27.

yii2 is vulnerable to Use of Predictable Algorithm in Random Number Generator